Improvement in clamps for button-hole sewing-machines



Patented March 11, 1873.`

W CHICKEN y(Ilmpys for Button-Hole Sewing-Machines.

Zag f UNITED .STATES PATENT EEICE.

WILLIAM CHICKEN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO AMOS L.

WOOD, TRUSTEE, OF SAME PLACE.

IMPROVEMENT IN cLAMPs Foa BuTToN-HoLE SEWING-MACHINES.

Specification forming part of Letters Patent No. 136,702, dated March 11, 1873.

To all whom t may concern:

Be it known that I, WILLIAM CHICKEN, of Boston, in the county of Suffolk and State of l Massachusetts, have invented certain Improvey ments in Clamps for Button-Hole Machines;

and I do hereby declare that the following, taken in connection with the drawing which accompanies and forms a part of this specification, is a description of my invention sufficient to enable those skilled in the art to practice it.

My invention relates particularly to the construction or arrangement of the cloth-clamping mechanism of that class of button-holestitching machines shown in United States Letters Patent issued to me, No. 115,163. In such machines two clamp-feet are used for securing the work to the work-plate on each side of the button-hole slit, these feet being pivoted to the ends of two levers, which are so arranged as to be capable of being thrown down or raised to cause the feet to clamp or unclamp the work, and of being swung laterally to spread the feet and open the slit, more or less.

In the clamp mechanism, as usually made, the feet are raised by springs, and are spread byan eccentric or cam operated by a springlever, which has notches springing over a stationary tooth to lock the eccentric in position.

In my 'present invention I carry the clamplevers through slots at the opposite end of a cross-head, which cross-head is connected by a link to an eccentric lever which turns on a pin extending from an upright, so that the clamp-feet are not only pressed down y the eccentric, but are positively raised by i and the clamp-levers are spread by a lever having eccentric slots into Which two pins extend from the opposite levers turning this lever, causing the pins to positively move the clamplevers laterally in either direction; This arrangement is more simple, effective, and reliable than the common construction.

My invention consists in the improved mechanism for raising the clamp-levers and moving them laterally.

'Ilhe drawing represents'a work plate and clamp mechanism embodying my invention.

Figure 1 shows the mechanism in plan; Fig.

2 is a side View of it Fig. 3 is an end view of it, looking from the left of Fig. 1.

a denotes the work-plate. b o are the two levers, having pivoted to their front ends the -two feet d e, by which the work is clamped to tric lever, k, and sliding on this stem is the crosshead l, having at its opposite ends slots or forks m through which the levers b c pass, the eccentric surface acting against this crosshead (when pressed down) to depress the springs and cause the feet to clamp the Work;

From the rear side of the cross-head a piece, n, extends through a slot, o, in a link, p, jointed to the rear face of the eccentric lever, and as the lever is turned up into or toward a vertical position this link positively raises the cross-head, and thereby lifts the clamp-feet from the work. Behind the cross-head pins :v extend from the levers b c into slots q r, in two opposite arms of a lever, s, fulcrumed at t, and having a handle, u. The slots q r are eccentric to the center of movement of the lever, and as the handle u is turned in either direction the slots operate upon the pins to spread the levers or to move them inwardly, and to lock them in any position to which they may be brought by the action of the lever and its slots.

By this arrangement all springs are dispensed with; the clamp-levers are moved positively in each direction; the mechanism is easily operated Without special skill, and the parts are strong and cannot be easily got out of order in any way.

By arranging the mechanism that operates the levers, as shown, to adjust the clamp-jaws laterally, said jaws may be moved to the slightest extent and locked in position, their motion not being controlled by mechanism that is only capable of movements determined by the distance between teeth or notches.

`I claim- 1. In combination with the clamp-levers and "2 v ieenoe the eccentric for depressing hen, 1113 link p, substantially as described, whereby the jaws or its equivalent, for raising the levers, sub= are positively moved laterally to .enyreqnired stantially as described. extent, however slight, and are positively held 2. In combination with the levers b e, the in any posit-ion to which they are brought. lever s, having the eccentric slots q r through Executed this 23d day of September, A. D. which the lever-pins It extend, the lever s op- 1872. l

erarting to spread the levers b c, or to draw l WM. CHICKEN. them inward and to lock them in positiona.ll substantially as described. Witnesses:

3. 1n a clamp for button-hole stitching-ma- FRANGIS GOULD, chimes, clamp-jews eoinbiurd with mechanism, M. W. FROTHINGHAM. 

